Somewhat depends on the wheel and tire combination. A narrower wheel with a wider tire (within reason obviously) can help with keeping the bead seated. Some wheels have a little more agressive bead lip. I aired down to under 10PSI with Goodyear MTRs on cheap steel wheels.
Agreed, the right rear looked like it but if it was hanging on to a rock ledge with 1/4 of the tire width it would deform the tire pretty easily. We probably won't know unless they tell usThe second video made it look like they aired down somewhat; no idea what PSI.